In a communication or data network like a home network, through which smart devices, such as computers, televisions, appliances, etc., may be connected through wireless and/or wired communication channels to a computer, a television, etc., an admission request for transmitting an information flow to the network has been selectively granted to keep an overall network load to a level below a maximum capacity of the network. As referred herein, smart devices that are connected to the communication network are communication stations (hereinafter, “stations” for short) that communicate with one another via the communication network.
If all things were equal for stations connected to a network, that is, the station had more or less the same transmission rates, information flows with more or less same priorities, etc., network resources may be fairly distributed among stations by granting an equal time of network access to each station. However, stations connected to a network often have communication channels with different transmission rates and information flows with different priorities. For instance, in a wireless local area network (LAN), a data rate of a communication channel depends on varying channel conditions, such as path loss, shadowing, fading, etc. and on distances between stations and an access point.
Because of varying channel conditions and different distances between stations and an access point, especially in mobile stations, stations connected to a network through communication channels that have varying channel conditions and/or varying distances between the stations and an access point often vary their transmission rates to adapt to the changing transmission conditions.
With respect to stations connected to a network with varying transmission rates as discussed above, one conventional way of determining an admission request by a station for transmitting an information flow to a network has been to favor a granting of a maximization of an overall throughput of information flow in the network by granting admission requests of stations with relatively high transmission rates. However, the throughput maximization approach often discriminates stations with relatively low transmission rates by denying admission requests from those stations, even when information flows from such stations are of relatively high priorities in comparison to the priorities of information flows from stations with relatively high transmission rates.
Another method has been to use a required time fraction to ensure that a sum of the required time fraction for a station's flow and required time fractions associated with other admitted information flows does not exceed a predetermined limit. This method may consider a cumulative distribution function of channel data rate for a communication channel between each station and the network in estimating the required time fraction for a station to achieve a particular throughput and thereafter making an admissions control decision. However, this method does not give a fair consideration to relative priorities of information flow.
Although there have been recent attempts to control admission requests for transmitting an information flow to a network with variable channel data rates and prevent overloading the network, such attempts have proven to be less than successful because the proposed solutions are inefficient in assigning network resources fairly among different stations connected to the network.